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图1为应用最常规的野外震源组合的空间滤波特性。这种响应曲线的主要波瓣一般限于波数1/e(式中 e 为向上移动的间距)。实际上,波瓣的变化响应使滤波在15至20dB 范围内有效。图1中为18dB。在 f—k 域中,可控震源组合的时-空滤波特性可产生矩形震源振幅谱(见图2)频率间距与扫描的低频(F_L)和高频(F_H)极限有关。波数变化范围可由+1/e 到-1/e。然而,实际信号的振幅谱,如图3所示,其边棱以速度(V_L)为界的切割滤波极为相似。在振幅谱底部划两条对角线,在这些界限之外,强能量相当于地滚波。这种现象可在该谱的底部两角见到。
Figure 1 shows the spatial filtering characteristics of the most conventional field source combinations. The main lobe of this response curve is generally limited to the wavenumber 1 / e (where e is the upward moving distance). In fact, the changing response of the lobe makes the filtering effective in the range of 15 to 20 dB. 18dB in Figure 1. In the f-k domain, the time-space filter characteristics of the vibroseis combination produce a rectangular source amplitude spectrum (see Figure 2). The frequency spacing is related to the low frequency (F_L) and high frequency (F_H) limits of the sweep. The wave number can range from +1 / e to -1 / e. However, the amplitude spectrum of the actual signal, as shown in Figure 3, is very similar to the cut filter whose edges are bounded by the velocity (V_L). Draw two diagonal lines at the bottom of the amplitude spectrum. Outside these boundaries, the strong energy is equivalent to the ground roll. This phenomenon can be seen at the bottom of the spectrum.